NSF Award
1531475
A high-speed laser-based imaging system is a primary tool for researchers working in the area of fluid mechanics, combustion, and physical chemistry to illuminate the complexities of these harsh flowfields. The system is able to measure time-resolved, species-specific scalar fields and three-dimensional velocity fields to understand the initiation and propagation of combustion in high-speed flows as well as the early development of turbulent flows. This technology provides unprecedented access to the details of the physics of turbulent reacting flows influenced by mixing as well as transitional boundary layers. The new instrumentation will be utilized for both research and student training at Lafayette College, a private liberal arts college with engineering located in Easton, PA. The system will also be used to provide undergraduate students with meaningful involvement in many state-of-the-art research programs across several departments. Additionally, the velocimetry and high-speed visualization capabilities will be incorporated into junior level and senior level courses offered by both Mechanical and Chemical Engineering. Chemistry students will have the opportunity to perform fluorescence experiments and time-correlated spectroscopy measurements in new laboratory experiences. The system will significantly augment the ability to involve undergraduates of diverse backgrounds in meaningful research as well as incorporate advanced research capabilities into the undergraduate curriculum.<br/><br/>The proposed high-speed laser-based imaging system enables a wealth of diverse optical techniques to be applied to the study of mixing and combustion in compressible flows and the characterization of coherent structures in turbulent boundary layers. It will dramatically augment the capabilities of existing fluid dynamic, combustion, and physical chemistry research facilities at Lafayette, specifically supporting several research components: i) Examining the role of mixing efficiency and finite rate chemistry on non-premixed combustion in hypersonic flows, ii) Exploring ignition, flameholding, and extinction phenomena using time-resolved imaging of pre-mixed hypersonic reactive flow, iii) Characterizing the development and entrainment behavior of hairpin vortices and turbulent spots and the roles they play in turbulent and transitional flows. iv) Assessing the combustion properties of specialty biodiesel fuel blends, v) Measuring the phosphorescence lifetimes of organic thin film materials utilizing time correlated single photon counting, and vi) Generating reactive oxygen and measure quenching rates due to interaction with thiols to determine their detoxification capability in freshwater environments. Each of these research areas relies on the high-speed, high-power, tunable illumination and imaging capabilities enabled by this system.
